Endoscopic vessel harvesting (EVH), particularly of the greater saphenous vein in the leg and the radial artery in the arm, is a surgical procedure for obtaining a graft vessel for a coronary artery bypass graft (CABG) procedure. A physician's assistant (PA) typically performs the EVH on one or both legs and/or arms of the patient by operating endoscopically with instruments actuated at a position remote from the operating site to harvest saphenous veins and/or radial arteries.
Because the vessels harvested during EVH are surrounded by tissue (of the arm or leg, for example), it is necessary to create an operative space so that the PA can dissect the vessel from the surrounding tissue. Operative space may be created by using insufflation, as is disclosed in U.S. Pat. No. 5,468,248, or by using mechanical retraction, as is disclosed in U.S. Pat. No. 5,902,315 or 6,592,604, the disclosures of which are hereby incorporated by reference. The insufflation method creates operative space by separating layers of tissue and then introducing a gas into the space between the layers to maintain the separation, whereas the mechanical retraction method simply uses a structure to hold the tissue layers apart.
Whether insufflation or mechanical retraction is used, the operator needs to manipulate the vessel to protect the vessel during the procedure by repositioning it within the operating field. For example, the vessel can be shielded by moving it away from a side branch when the side branch is transected. In this way, the vessel is protected from any injury that might be caused during that procedure.
One example of a device that provides for vessel manipulation is disclosed in U.S. Pat. No. 5,993,384. This device uses a “cradle” attached to a cannula that is movable from a first position when it is substantially housed within the cannula to a second position where it extends distally from the cannula. The wires to which the cradle is attached are bent such that when the cradle is extended, the cradle pushes the vessel away from the cannula. This solution may be non-optimal because the cradle has a limited number of available motions that make it more difficult to precisely position the vessel.
Another system for manipulating the vessel is disclosed in U.S. Pat. No. 5,902,315. In this case, a separate instrument (such as the Ethicon Endo-surgery vessel dissector) is inserted into the operative space to manipulate the vessel. While this approach allows for greater vessel manipulation, it has the disadvantage of requiring that the user must operate another instrument in the operating field.